Ten years Tycho-2
Catalogue
Dear coauthors and many
others,
The Tycho-2 Catalogue of the 2.5
million brightest stars in the sky was released on the 8th of February
2000, and we can celebrate the tenth anniversary enjoying that the
catalogue has been very well received.
The Tycho-2 Catalogue contains positions,
proper motions and two-colour magnitudes for the 2.5 million stars covering the
entire sky, and the authors are E. Høg, C. Fabricius, V.V. Makarov, S. Urban, T.
Corbin, G. Wycoff, U. Bastian, P. Schwekendiek, and A. Wicenec. Positions and
magnitudes were based on observations from 1989 to 1993 with the ESA
Hipparcos astrometric satellite. The Tycho-2 positions and 100 years of
ground-based astrometry contained in more than 140 catalogues were utilized to
obtain the proper motions. Publications and data are available at www.astro.ku.dk/~erik/Tycho-2.
2) The paper in Astronomy & Astrophysics
announcing the Tycho-2 (see website) was reprinted in 2009 in a special issue of
A&A, Vol. 500, p.583, with a commentary by Catherine Turon (see
website), as one of the 40 most cited among 50 000 papers published in the
journal during the 40 years since its foundation in 1969.
2) Nearly 700 citations of the A&A paper
since 2000 are presently recorded at the SAO/NASA Astrophysics Data System
(ADS), but many applications do not result in recorded citations, as pointed out
under items #4 and 5.
3) The positions, proper motions and
two-colour magnitudes of Tycho-2 are widely used for all kinds of astrometric
and astrophysical studies. Among the hundreds of catalogues available at the
VizieR in Strasbourg it is the 4th most popular after the 2MASS, the USNO-B1.0
and the Hipparcos and Tycho Catalogues, and the VizieR mirrors have recorded a
number of up to 600 000 interrogations per month, according to Turon's
paper. The corresponding maximum number for the Hipparcos Catalogue is 940
000.
4) The practical more technical applications
should be particularly mentioned. For preparation of observations and control of
telescope setting on the ground and for monitoring and control and of
satellite attitudes and orbits, the Tycho-2 is the catalogue of choice. These
applications appear as citations in the technical papers, but since most of
them are either project internal or at least not refereed there are no real
citations which would be counted at ADS.
5) A quotation related to the technical
applications of item #4 is of interest. Andreas Wicenec, co-investigator on
the Tycho project since 1983, and then since many years at ESO, Garching,
wrote to me last year: "I'm missing one very important use case in
Catherine's very nice paper: Observation preparation and support for observatory
operations. I'm mentioning this because when I've seen the requirements for the
implementation of a catalogue to be used for the optical pointing tests of the
ALMA antennas, it was immediately clear that there is no other choice than
Tycho-2. This is mainly due to the magnitude range and the proper motions (I had
to add parallaxes though). For this reason we have implemented Tycho-2 servers
for ALMA in all instances of the ALMA archive installations, including the many
test installations around the world."
---------------------------------------------------------------------------------------------------------------------------
On behalf of all participants in the Tycho
project, I acknowledge again the support we have received from ESA, the
Hipparcos Science Team, and all national funding authorities.
With best regards
Erik Høg
Niels Bohr Institute
Copenhagen University
25 Jan. 2010